446 SCIENCE PROGRESS 



just published, deal with silver ores (6s. net) and petroleum (55. net.) These 

 have been prepared mainly by Mr. H. B. Cronshaw, Ph.D., A.R.S.M., and 

 maintain the high standard of the series. They contain an exhaustive 

 account, geographical, technical, and statistical, of the occurrence of these 

 products throughout the world, together with a full bibliography of the 

 principal publications concerning the subject of the monograph. 



Constable and Company have just published a life of the great Metchnikoff, 

 written by his widow, Olga. This book, describing the evolution of a great 

 mind, of a character, and a human life, is an interesting psychological document. 

 It reveals the life of a man who seems to have had a hard struggle in the early 

 stages of his career. We have noted here some of the more remarkable facts 

 brought out in Madame Metchnikoff's book. 



When a young man, Metchnikoff persuaded his parents to allow him to 

 go to study at Wiirzburg, where the celebrated Kolliker was lecturing. 

 Thinking that in Germany the terms began in September, as in Russia, he 

 arrived too soon, and, alone for the first time among strangers, felt completely 

 lost. He was given the addresses of some Russian students, who, however, 

 received him so coldly that he was seized with despair and immediately returned 

 home to Russia. 



Later, at Heligoland, Metchnikoff worked out a curious case of alternation 

 of generations in certain parasitic nematodes. Delighted with his discovery, 

 he hastened to communicate it to Leuckart. The latter appropriated 

 Metchnikoff's discovery as his own and published it under his own name. 

 In his despair, the youth confided in Claus, another German Professor of 

 Zoology, who told him that Leuckart was in the habit of such dealings. 

 Later Metchnikoff, at Gottingen, was given a valuable lizard to anatomise 

 and describe. Elie was not good at technique, on account of his nervous 

 temperament ; he made a " mess " of the lizard, threw it across the room, 

 and left that laboratory soon after. 



Metchnikoff was ever a rebel against social conventions. At Odessa, 

 Cienkovsky, a man of great European culture, tried to take him in hand : 

 he reproached Metchnikoff with a lack of self-control, and undertook the 

 paternal task of civilising this impulsive, fiery, and often violent young man. 



He preached him tolerance towards the opinions of others, and strict 

 self-discipline. Later on, after the death of his first wife at Madeira, Metchni- 

 koff, a prey to morbid thoughts, said to himself: "Why live ? My private 

 life is ended ; my eyes are going ; when I am blind I can no longer work ; 

 then why live ? " He then took a dose of morphia. He did not know, 

 however, that too strong a dose, by provoking vomiting, eliminates the 

 poison. He recovered from this attempt to commit suicide, and later turned 

 once more to science. [Life of Elie Metchnikoff, Constable, 1921.) 



The Report of the Food Investigation Board for 1920 (H.M. Stationery 

 Office, price is. net) contains a summary of a good deal of interesting 

 information which has been obtained by the several Committees of the Board. 

 The Engineering Committee is now in a position to report the results of its 

 investigations of the flow of heat through walls and of the thermal conductivity 

 of various insulators. It is found that the heat-flow through the solid parts 

 of a heat insulator is negligible compared with that due to convection currents 

 in the air contained in its pores. Thus, the specific conductivity of a particular 

 substance, e.g. cork, depends much more upon the form and size of the air 

 spaces — that is, upon the " packing " of the substance — than upon the 

 specific conductivity of the material considered as a continuous solid — a 

 result which explains the want of agreement in the thermal conductivity 

 assigned by different observers to the same substance. It was, moreover, 

 unexpected, because of the small dimensions of the air spaces concerned. 

 The study of the mode of escape of heat from the surface of a wall has also 

 led to novel results. The chief source of loss is by convection currents set 



